As a child I read Groosham Grange from Anthony Horowitz, and when I first heard a description of Harry Potter, I thought that they were describing that book from Horowitz. I can't believe no one else noticed. But I also think that most people active in children's literature will have an attitude of "anything that gets a child reading, is a good thing", so they're not that upset about poor quality being popular and they'd rather keep the positive vibe going.